The invention relates to a circuit for regulating a parameter by means of a bidirectional structure under peak current control with stabilizing control by state feedback, and with or without metallic isolation.
The circuit of the invention may be used whenever a timevarying parameter is to be servo-controlled with high energy efficiency. Its applications extend to radar, to motor control, to D class amplification, to inverters, etc. . . . and regardless of the field in which it is used: space, aviation, consumer.
Nevertheless, the invention is also applicable to regulation that is continuous or slowly varying.
The state of the art makes use of regulator-modulator associations that operate in frequency space and in state space.
An application for a radar is described in the article by A. Capel, J. C. Marpinard, G. Sahet, M. Valentin and D. O'Sullivan, entitled "A bidirectional high power cell using large signal feedback control with maximum current conduction control for space applications" (ESA Journal, 1986, Vol. 10). It makes use of a buck regulator and a current controlled modulator, operating both with negative values and with positive values. The principle whereby the current flowing in the regulator i(t) is compared with a calculated current i.sub.M is such that:
the permanently measured current is the current flowing through the inductor downstream from the FET switches such that if a short circuit occurs at the shunt switch, the system does not apply current limitation since the measured current is zero;
the control law makes use of AC in the capacitor;
the control function Vc(t) has the form: ##EQU1##
the modulator makes use of the gains of the zero order blockers of the non-liner function multipliers and dividers.
The same publication describes another application for a radar making use of a buck cell with a simplified modulator. It differs from the above in that its control law does not make use the capacitor AC.
This concept does not make use of peak current control and it makes use of a comparator in the form of a pulse width modulator (PWM) function.
An object of the invention is to improve such a structure.